Arc Energy Resources has recently completed the weld overlay cladding of hull penetrator inserts destined for the UK’s Royal Navy’s new Astute class submarine, being built by BAE Marine Systems at Barrow-in-Furness. The project was commissioned by Cumbria-based specialist subcontractor Orwelco (Barrow) Ltd, which is producing the inserts on behalf of Seacon Phoenix, a manufacturer of underwater electrical and optical connectors and cable assemblies. The hull penetrator inserts, which as the name suggests are welded into the hull of the boat, are designed to allow external instrumentation connections to pass to the inside of the vessel. As the inserts are part of the main structure, they have to be made from the same type of high-strength steel as the hull itself. The steel lacks the corrosion resistance needed to ensure a secure seal for the Seacon connectors, so the internal and sealing areas that are exposed to seawater were weld overlay clad with Monel 400, a 70% nickel 30% copper alloy that is considered to be the ideal material for this environment.
